According to Fly Fish Food, the Stillwater is in full late-summer stealth mode right now: skinny, glassy, and clear enough that the trout can probably critique your casting. Flows are sitting around 382 CFS near Absarokee, with water temps at a pleasant 61.5°F. Morning is the easy money, with caddis and midges working the riffles before the sunshine gets serious. By late morning, it’s terrestrial season in earnest. Tan or purple hoppers and ants fished tight to grassy banks, cutbanks, and shaded edges should get plenty of attention. Keep a low profile, shorten the hero casts, and sneak upstream because these fish have a front-row seat to everything happening above them.
Once the thermometer starts reaching around the mid-80s, expect trout to abandon the bright stuff and check into deeper runs, boulder pockets, and shade. That’s a good cue to trade foam for Frenchies, Pheasant Tails, Pat’s Rubber Legs, or another heavier nymph that can rummage around near the bottom. Then keep an eye on the evening water from about 5 to 7:30, when BWOs can bring fish back upstairs and make tiny dries and emergers worth the squinting. The basic game plan is wonderfully simple: caddis early, hopper chaos around midday, nymph the hot afternoon hideouts, then go small for the evening rise.
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